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U.S. Department of Health and Human Services

Medical Devices

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Draft Guidance for Industry and FDA Staff: Class II Special Controls Guidance Document: Electroconductive Media


This guidance document is being distributed for comment purposes only.

Document issued on:  April 5, 2010

Comments and suggestions regarding this draft document should be submitted within 90 days of publication in the Federal Register of the notice announcing the availability of the draft guidance.  Submit written comments to the Division of Dockets Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, rm. 1061, Rockville, MD 20852.  Alternatively, electronic comments may be submitted to http://www.regulations.gov.  All comments should be identified with the docket number listed in the notice of availability that publishes in the Federal Register.

For questions regarding this document, contact Quynh Hoang at 301-796-6860 or by email at quynh.hoang@fda.hhs.gov.


U.S. Department of Health and Human Services

Food and Drug Administration

Center for Devices and Radiological Health

Ophthalmic Lasers, Neuromuscular Stimulators, and Diagnostics Branch

Division of Ophthalmic, Neurological, and Ear, Nose and Throat Devices

Office of Device Evaluation


Additional Copies

Additional copies are available from the Internet.   You may also send an e-mail request to CDRH-Guidance@fda.hhs.gov to receive a copy of the guidance.  Please use the document number (1571) to identify the guidance you are requesting.


1.  Introduction

2.  Scope

3.  Risks to Health

4.  Device Description

5.  Performance Characteristics

6.  Labeling

7.  Limitations of Exemption from Premarket Notification

Draft Guidance for Industry and FDA Staff

Class II Special Controls Guidance Document:  Electroconductive Media

1.   Introduction

This draft guidance document was developed as a special controls guidance for this class II device and to support the exemption from premarket notification (510(k)) requirements of the Federal Food, Drug, and Cosmetic Act (the act) of electroconductive media (see sections 510(m) and 513(a)(1)(B) of the act; 21 USC 360(m) and 360c(a)(1)(B)).  Electroconductive media are the conductive creams or gels used with external electrodes to reduce the impedance (resistance to alternating current) of the contact between the electrode surface and the skin.

This draft guidance is being issued in conjunction with a Federal Register notice announcing a proposal to designate a special controls guidance and to exempt this device type from the premarket notification requirements of the act if the manufacturer follows the recommendations in the special controls guidance document.  This guidance is issued for comment purposes only.  If a final rule is not issued designating this guidance as a special control, then the guidance will not be issued in final form.

This draft guidance document describes a means by which electroconductive media may comply with the requirement of class II special controls (513(a)(1)(B) of the act).  Designation of this guidance document as a special control will mean that manufacturers of electroconductive media will need to address the issues identified in this special controls guidance document.  However, if the regulation is finalized designating this guidance as a special control, a manufacturer need only show that its device meets the special controls by following the recommendations of the guidance document or in some other way providing equivalent assurances of safety and effectiveness.  Under section 510(m), FDA is also proposing to exempt from the requirement of premarket notification certain devices falling within this classification.  If the proposed rule is finalized, manufacturers who follow the specific measures recommended in this guidance will be able to market their device without being subject to the premarket notification requirements of section 510(k) of the act, subject to the limitations on exemption in 21 CFR 882.9.1  Manufacturers who choose to provide other equivalent assurances of safety and effectiveness will need to submit a 510(k) and receive marketing clearance for their device.

2.   Scope

The scope of this document is limited to electroconductive media, 21 CFR 882.1275 (see below), class II, product code GYB.

Section 882.1275  Electroconductive media—

Identification.  Electroconductive media are the conductive creams or gels used with external electrodes to reduce the impedance (resistance to alternating current) of the contact between the electrode surface and the skin.

3.   Risks to Health

In the table below, FDA has identified the following risks to health associated with the use of electroconductive media.  We recommend the following measures to mitigate the risks identified in this guidance document.

Identified riskRecommended mitigation measures
Adverse skin reactionsSections 5 and 6
Inaccurate clinical diagnosis based on impaired quality of the recorded physiological signalSections 5 and 6


4.   Device Description

Under 21 CFR 820.181(a), the device master record must include or reference the following, for each type of device:

  • specifications, including appropriate drawings
  • composition
  • formulation
  • component specifications
  • software specifications. 

Accordingly, we recommend that you maintain a complete description of the device and all accessories in the device master records.  This description should include the following:

  • identification of the device, by the regulation number and product code described in Section 2 above
  • a written description of all ingredients and concentrations of the gel formulation
  • identification of the pH of the gel formulation
  • a description of the function of each gel ingredient (e.g., preservative, colorant)
  • identification of the volume and/or weight of the device.

5.   Performance Characteristics

Under the Design Controls section of the Quality System Regulation (21 CFR 820.30), each device manufacturer must establish and maintain procedures to control the design of the device in order to ensure that specified design requirements are met.  In meeting the design validation component of these design control requirements, each manufacturer must validate its device design, i.e., establish by objective evidence that device specifications conform to defined user needs and intended uses (21 CFR 820.3(z)(2)).  The results of design validation must be documented in the design history file (DHF) (21 CFR 820.30(g)).  We recommend that manufacturers evaluate their devices as described below and, where appropriate, document the results in their design history files as a part of the Design Controls requirements (21 CFR 820.30).  We recommend that you also maintain the information below in your device master records (21 CFR 820.3(j)) to document your device’s specifications and performance characteristics.

We recommend that you evaluate and document the electroconductive medium’s biocompatibility, electrical performance, and stability to assure that the device performs as intended.

A.  Biocompatibility

The electroconductive medium (gel) should be biocompatible for its intended use.  To determine the applicable device category and tests, you should consult ANSI/AAMI/ISO 10993-1:2003, “Biological evaluation of medical devices -- Part 1: Evaluation and testing.”  This FDA-recognized standard recommends evaluation and testing of medical devices based upon the duration and type of contact.  For electroconductive media with a limited contact duration (e.g., less than 24 hours), we recommend the following tests to establish material safety: dermal irritation, sensitization, and cytotoxicity.

The electroconductive medium should be tested under its intended conditions of use, e.g., duration and method of application.  The medium should not contain or produce toxic or electrolytic products that could result in an irritating, sensitizing or cytotoxic effect upon the skin or enter beneath the skin by iontophoresis.  However, due to the electrolytic composition of some electroconductive gels that contain high levels of saline, a positive cytotoxicity result may not be a correct indication that the hydrogel is truly cytotoxic.  In these circumstances, evaluation using other tests specified in the standard may be appropriate.

B.  Electrical Performance

The electroconductive medium should be effective in conducting electrical current across the electrode-skin interface.  We recommend that you perform impedance testing to assure that the electroconductive medium has conductive properties that are appropriate for the device’s intended use.

C.  Stability

Electroconductive media should be stable and resist physical and chemical breakdown as a result of conducting electrical current and extended periods of storage over a range of environmental conditions.  We recommend that you perform testing to establish, for labeling purposes, the device’s shelf life and storage conditions.

6.   Labeling

The following suggestions are intended to help you prepare labeling that satisfies the requirements of 21 CFR Part 801.2

Package Insert

We recommend that you provide a package insert with the device.3  The insert should include the following:

  • identification of the model number and name, and volume or weight
  • date of manufacture, shelf life, and lot number
  • list of ingredients
  • storage instructions
  • adequate directions for use, including instructions regarding maximum duration of use and procedures for application of the gel to the electrode surface and removal of the gel from the electrode and skin following use.

Your device labeling must include adequate directions for use in accordance with 21 CFR 801.5.  Under this rule, your labeling (e.g., package insert) must describe the intended use of the device, and include a listing of contraindications (if applicable), warnings, precautions, and adverse reactions, relevant to your device (21 CFR 801.5(a)).  This information must be prominently placed on the labeling (21 CFR 801.15).  The labeling recommendations below are not intended to capture all possible limitations or instructions for all electroconductive media.  Therefore, when developing adequate directions for use, it may be necessary for you to include additional limitations (e.g., contraindications, warnings, precautions, adverse reactions), and other instructions that are appropriate for your device, depending on its specific design, features, and performance characteristics.

Intended Use

The electroconductive media covered by this guidance document are those intended for use with external electrodes for the purpose of reducing the impedance of the electrode-skin interface.


We recommend that the package insert advise users of the following:

  • The electrode gel is for external use only;
  • The electrode gel should be applied only to a clean electrode that is placed over normal, intact, clean, healthy skin;
  • The electrode gel should not come into contact with open wounds or rashes, or over swollen, red, infected, or inflamed areas or skin eruptions, e.g., phlebitis, thrombophlebitis, varicose veins;
  • The electrical performance characteristics of the electrode gel may affect the safety and effectiveness of electrical stimulation and recording; and
  • The electrode gel should not be reused.


We recommend that the package insert advise users to keep the electrode gel out of the reach of children.

Adverse Reactions

We recommend that the package insert include known adverse reactions to the electrode gel, such as skin irritation or hypersensitivity.

7.   Limitations of Exemption from Premarket Notification

FDA’s decision to exempt a class II device from the premarket notification requirement of the act is only to the extent that the device has existing and reasonably foreseeable characteristics of devices within that generic type that currently are, or have been, in commercial distribution.  Section 21 CFR 882.9 specifies the limitations on exemption.  If any of these limitations apply, your device is not exempt, and you must submit a premarket notification.


1.  We recommend that manufacturers document how they address the recommendations of this guidance in their design history file.  Manufacturers must maintain design controls, including a design history file, in accordance with 21 CFR 820.30.

2.  Labeling must comply with the requirements of 21 CFR Part 801 before a medical device is introduced into interstate commerce.  Labeling recommendations in this guidance are consistent with the requirements of 21 CFR Part 801.

3.  Devices not restricted to prescription use must contain adequate directions for use in accordance with 21 CFR 801.5 and section 502(f) of the act.